Article ID: 171668
Article Last Modified on 3/24/2000
APPLIES TO
- Microsoft Visual FoxPro 5.0 Standard Edition
- Microsoft Visual FoxPro 5.0a
This article was previously published under Q171668
SYMPTOMS
When using optimistic table buffering on a table inside a database container (DBC), a shared table remains locked after a table update that occurs within a transaction. This situation prevents other users from updating the table. The behavior occurs when the table is in a DBC, the table update is within a transaction and the buffer mode is optimistic table. The behavior does not happen when the table is free.
RESOLUTION
One resolution is to use free tables instead of tables within a database.
Another option is to check, within the transaction, whether the table is locked (ISFLOCKED() returns True) and if the table is locked, use the UNLOCK command to unlock the table.
A third resolution to perform a REPLACE on more than one record is to put the REPLACE statement within a loop so that the scope of the REPLACE statement affects only a single record.
STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This has been corrected in Visual FoxPro 6.0.
MORE INFORMATION
NOTE: This problem occurs only when the scope of records affected by the REPLACE function is more than one.
Steps to Reproduce Behavior
The following code will demonstrate the behavior:
* Start of the Code CLEAR CLOSE DATABASES ALL SET MULTILOCKS ON SET SAFETY OFF SET TALK OFF * Create the database and table ********************************************************************* * NOTE: If the table is not in a database the problem does not occur. * The following line can be removed to verify this behavior. ********************************************************************* CREATE DATABASE test CREATE TABLE test (CTest C(10) , NTest I) INSERT INTO Test VALUES ( "one", 1) INSERT INTO Test VALUES ( "two", 2) INSERT INTO Test VALUES ( "three", 3) INSERT INTO Test VALUES ( "four", 4) CLOSE DATABASES ALL USE Test SHARED =CURSORSETPROP( "buffering", 5) && Optimistic Table Buffering REPLACE NEXT 2 cTest WITH "test" BEGIN TRAN IF NOT TABLEUPDATE( 2, .F., "Test") ? "Failed." ELSE ? "Committed." ENDIF END TRAN IF ISFLOCKED( "Test") * UNLOCK in test && Uncomment this line to test the UNLOCK command ? "The table is still locked." ELSE ? "The table is not locked." ENDIF ?ISFLOCKED() * End of the Code
Keywords: kbbug kbfix kbvfp600fix kbprb KB171668